Not By Blood
by LadyPeck
Summary: Spock doesn't want to feel this way about the girl he's supposed to see as a sister, but anger and hormones blend into a mix of love and hate, and sexual encounters that leave them confused and torn. Will adulthood bring clarity?


No one would understand his desires. His parents wouldn't. His fellow officers. Being honest with himself Spock didn't understand it. He simply accepted it, and kept the feelings to himself. The girl he'd once thought of as a sister had broken his heart, and for awhile even his mind. He had pretended to be unaffected by her apology when she came to explain why she'd rejected him, called him names, and then walked out that night.

At some point he'd stopped pretending he understood and treated her with cool indifference. It wasn't until he was nineteen years old and hit puberty, grossly early for a Vulcan, that his feelings regarding his foster sister shifted from indifference to naked hostility, because it wasn't until he hit puberty that he began to realize Michael Burnham was female, and just how powerful sexual attraction could be.

She had breasts. She had developed a curve to her hips, and other places, that her own turn with puberty had developed in her. She even smelled different at different times of the Earth Standard Month by which she and his mother measured their lives and their menstrual cycle. That scent deeply affected him.

The change in her scent began about a week before she bled. It was at that time he reacted in ways that shamed him. The smell incited a visceral response that made him wonder, every time it happened, if he was going through the pon farr. He'd awaken with a racing pulse, sweating, and those damned erections that plagued him.

It wasn't just her reproductive cycle that affected Spock. Her body did. Michael would exercise in tight shorts. He'd look at the shape of her body, the roundness of her ass, the way her thigh muscles flexed, and, of course, what was between her legs, and he'd harden with startling speed and intensity, and every time he hated himself for the reaction. Every time he loathed her, blamed her, for something he couldn't control, much less she. That created a sense of guilt, which made him angry, and during that viscous cycle of lust and self-loathing, he was fully aware that Michael wasn't at fault. Neither of them were, yet he was powerless to not feel the way he did. It was all so damned illogical.

Their years coexisting as teens in the same house did more damage than anything else that happened between them. He hated his changing body. He hated the lust he felt for her, and his struggle to hide it.

"She is your sister," Sarek had reminded him once.

"Not by blood."

The night she came home from graduation, tipsy from drink she'd indulged alone on a bluff overlooking Forge Valley, because she hadn't been invited to celebrate with her classmates, he'd watched her try to sneak into the house. She leaned on him as he'd helped her to her room, and before he could leave she'd asked for help getting ready for bed. He'd obliged, only to find himself with his face inches from her exposed thighs. He had a clear view of her white panties, and he could smell her.

It was madness to reach for her, to rub a thumb clumsily over her, hoping his vague knowledge of the human female anatomy served him well enough to touch her clit, arouse her. She'd gasped, blinked at him with glassy eyes, thinking perhaps it had been a mistake, an accident, but the second stroke couldn't be dismissed as anything innocent.

He'd pushed her back, onto her bed, his big hands clumsy as he pulled at her panties, smelling her arousal getting stronger, and his erection throbbing between his thighs, as he continued stroking her.

"You're my brother."

"No, I am not. Tell me you want it. Tell me and I'll give it to you."

"I…I…want it. Don't stop."

He'd tasted her then. Licked at her pussy without any experience or finesse. He poured longing, lust, and years of hurt into eating her and was rewarded with stifled moans she released into her pillow. He prayed the privacy dampeners covered the sounds of his wet fingers sliding into her. Or his own moans escaping as her juices dribbled down his chin and he jerked himself off to the taste of her heated flesh against his tongue.

When it was over Spock stood, tucked himself away, and left her with her panties around her ankle, her thighs spread wide, her face covered by her pillow, body shaking with sobs of guilt and shame. He felt the same, but he shoved those feelings down. Buried them, and fell asleep without difficulty.

They pretended nothing had happened for months after. Then he came home to find their parents gone to some diplomatic function at the Tellarite embassy. As soon as he'd looked into her eyes that night came back. Only this time there was no shame. This time there was only lust. He gave in to the primal urges within and threw Michael over his shoulder, ran up to his room with her, and without care or an attempt at pleasing her, ripped her dress away and thrust into her. She'd cried out in pain, making him impossibly hard. He felt her get wetter with each thrust until she was dripping over his balls and down his thighs.

"Spock! Spock please!"

She cried his name with every thrust, begging him for mercy, gentleness, that he denied, never stopping to consider it was her first time, too, but she never asked him to stop. He felt her nails dig into his shoulders as she held on, sobbing from pleasure and pain, her own hips rolling against him, grinding hard. He was brutal, holding her in the air, her body helpless in his arms like a rag doll. She kissed him, bit his lower lip and drew blood, which aroused him even more. Lust was a monster in their bellies, and they fed it by dropping to his bed, thrusting, scratching, screaming. She rode him, and he watched her in the mirrored glass of his bedroom wall as she came explosively, watched her pussy gush with every thrust, felt the wet heat of her soak both him and his sheets, putting a scent in them he'd never forget.

Spock wanted her to stay, wanted her to share his bed, but didn't have the words or the bravery to ask. Michael left his bedroom on unsteady legs, naked, her ruined dress and underwear his to do with as he pleased. She never returned to his room. She studied half way around the planet. Joined Starfleet, then took the assignment on the Shenzhou, never reaching out to him, nor he to her. He hated her once again for leaving him. Abandoning him. Rejecting him.

Now, on Discovery, they've found peace. Their encounters from years past are an unspoken thing that he doesn't expect her to bring up, so Spock is surprised when Michael shows up at his door in the dead of night. She stands at his window, watching space streak by at warp, silent.

"Something troubles you?" he prompts.

She turns to him, a slight smile on her lips, before reaching up and pulling his coat open, and then down his arms, until it falls to the floor, and he knows she's not there to talk. At least not with words. Her hand on the center of his chest is much gentler than any hand he's ever touched her with. She pushes him to the chair beside the port. He removes his shirt without word. There's no need to question it. To fight it by calling her sister, or him brother. They haven't been siblings in years, if ever. He's hard for her before she can undo his trousers and pull him free.

"I should've been gentle the last time. Treated you with respect. It was your first time, too," he says.

"You hated me, Spock."

"I'm sorry."

"I hated you too, as much as I wanted you. We've put that behind us. Let's have this while we can. Let's be…human. Let me see a side of you I never have."

When Michael takes him into her mouth she does so with considerably more expertise than he possessed all those years ago with her. When he reciprocates he does so with skill that makes her cry out with pleasure untainted by pain, or shame. There's no resentment in the roll of her hips, or anger when he thrusts into her. Neither hide the sounds of their pleasure. Their hands are gentle, their kisses deep and slow. There's love and respect in the act, as much as there's lust. Spock let's Michael feel his desire, hear his pleasure, see the love he feels for her in his eyes. After, when he carries her to his bed, their bodies sweaty and sated, they lay there in contentment. Peace.

"Is that another smile?"

Spock strokes her arm with gentle fingers. "Indeed it is."

She falls asleep first. He remains awake to enjoy the feel of her in his arms, the taste of her in his mouth, and without any hurry to hide the smile that lingers upon his lips.


End file.
